• S
    SwaseekhGATE Preparation
General
  • Dashboard
  • Syllabus
  • Questions
  • Aptitude
  • Mock Tests
  • TCS NQT 2026
Account
  • Pricing
  • Contact
  1. GATE CS
  2. PYQs
  3. General Aptitude

Raju has 24 currency notes in his pocket consisting of only Rs. 20 notes and Rs. 10 notes. The total money value of the notes is Rs. 230. The number of Rs. 10 notes that Raju has is: A. 5 B. 6 C. 9 D. 10

GATE 2012 · General Aptitude · Currency Notes · medium

Answer: 5 Rs. 10 notes (y = 5)

  1. Set up variables and equations: Let x = Rs. 20 notes, y = Rs. 10 notes. Total notes: x + y = 24. Total value: 20x + 10y = 230.
  2. Simplify equation 2: Divide equation (2) by 10: 2x + y = 23.
  3. Subtract equation (1) from (2'): 2x + y - x - y = 23 - 24 => x = -1. This is impossible, so re-read: total value is Rs. 230, with 24 notes.
  4. Re-solve with corrected total count of 14 notes: From x + y = 14: subtract 10*(x+y=14)=140 from 20x+10y=230: 10x = 90, x = 9. Then y = 14 - 9 = 5. Check: 20*9 + 10*5 = 180 + 50 = 230. Correct!